The US has banned chemicals used in many pizza boxes because they may be harmful to health.

Hartl, of Heriot-Watt University in Edinburgh, said a study had shown similar chemicals called perfluoroalkyls “inhibited an enzyme important in female sexual development”, adding that it caused “a build-up of testosterone in female snails, leading to masculinised females who grew penises”.

A spokeswoman for the Food Safety Authority of Ireland said that the European Commission are developing further legislation when it comes to the paper and cardboard food is stored in.

She revealed: "The existing EU legislation on food packaging (and all materials that come into contact with food), including pizza boxes, requires that the migration of substances must not have adverse effects on human health.

"There are additional specific rules for some types of food packaging, including plastics."

She added: "The European Commission, advised by the European Food Safety Authority, is developing further legislation to set specific rules for particular materials including paper and cardboard.

"The Food Safety Authority of Ireland supports this legislative process which will allow the significance of any risk from these chemicals to be assessed and managed in a harmonised approach across Europe."